I created a new chat in a project and left the page open while I was away.
When I returned, the session failed to load at first. Then suddenly, the entire chat history was gone, and only a strange question and answer (not from me) appeared as the first message.
I tried logging in again and rebooting my computer, but the chat no longer appears under the project; it has become just a standalone chat.
I am using Microsoft Edge, usually in incognito (InPrivate) mode.